[Extensions] Remove SyncExtensionFunction

extensions/browser/extension_function.cc

Index: extensions/browser/extension_function.cc
diff --git a/extensions/browser/extension_function.cc b/extensions/browser/extension_function.cc
index 942f1a8f4262e655ca714dd129f47f8170e9b3f0..adbb62df7765cc41f296748a713e1968b6d20bf5 100644
--- a/extensions/browser/extension_function.cc
+++ b/extensions/browser/extension_function.cc
@@ -620,19 +620,3 @@ bool AsyncExtensionFunction::ValidationFailure(
     AsyncExtensionFunction* function) {
   return false;
 }
-
-SyncExtensionFunction::SyncExtensionFunction() {
-}
-
-SyncExtensionFunction::~SyncExtensionFunction() {
-}
-
-ExtensionFunction::ResponseAction SyncExtensionFunction::Run() {
-  return RespondNow(RunSync() ? ArgumentList(std::move(results_))
-                              : Error(error_));
-}
-
-// static
-bool SyncExtensionFunction::ValidationFailure(SyncExtensionFunction* function) {
-  return false;
-}